Method of repairing cracks in cylinder blocks



July 26, 1955 H. K. TREADWELL METHOD OF REPAIRING CRACKS IN CYLINDER BLOCKS Filed July 29, 1949 INVENTOR. HORACE K. TREADWELL ATTORNEY United States Patent NIETHQD 6F REPAIRING CRACKS 1N (IYLENDER BLOiIKS Horace K. Treadweil, Zonesboro, Ga.

Application July 29, 1949, Serial No. 107,432

Claims. (CL 29402) This invention relates to a method of repairing cracks in cylinder blocks, and more particularly to a method of repairing cracks in cylinder blocks of liquid cooled internal combustion engines.

Many expensive cylinder blocks from engines of automobiles, trucks, tractors, buses and the like, are discarded each year because of cracks caused by freezing, by undue stress, or by rapid temperature changes. By far the greatest percentage of cracks in liquid cooled engines are due to freezing of the engines cooling fluid. Many different methods and products have been experimented with over a long period of years, but heretofore such methods and products tried have proved unsuccessful in producing permanent repairs.

An object of my invention is to provide an improved method of repairing cracks in cylinder blocks of internal combustion engines.

Another object of my invention is to provide a method and apparatus for making permanent repairs in cylinder blocks of internal combustion engines.

Another object of my invention is to provide an improved method for repairing cracks in cylinder blocks, which said method is simple and inexpensive to carryout, effective and permanent in result, and provide a neat and unobtrusive seal.

Other and further objects and advantages of my invention will be apparent from the following description taken in connection with the accompanying drawing in which like characters of reference designate corresponding parts throughout the several views, and wherein:

Fig. 1 is a top plan view showing apparatus embodying my invention installed on a cracked cylinder block.

Fig. 2 is a cross-sectional view taken along the line 22 in Fig. 1.

Fig. 3 is a cross-sectional view taken along the line 3-3 in Fig. 1.

Fig. 4 is a cross-sectional View taken along the line 4-4 in Fig. 1.

In the embodiment chosen for illustration, Fig. 1 shows a portion of a cylinder block 1!) of a liquid cooled combustion engine having a cylinder bore 11 and valve ports 12 and 13. As shown, the cylinder block has a crack 14 extending from the valve port 12 into the cylinder bore 11. According to my method for repairing such a crack, a hole is drilled with a #21 drill through the crack from the base of the valve seat recess 15 in the valve port 12 into the cylinder bore. This hole is started in the corner where the side wall joins the bottom wall of the valve seat 15, and the angular displacement of the walls together with the crack admits easy starting of the drilling operation. In the holethus drilled, a plug of A nickel alloy rod, commonly used for such purposes and available on the market as K 8: W plugging rod, is installed, as shown at 16 in Fig. 4, after threading the bore with a tap. Suitable rods for a somewhat similar purpose are shown in the patent to Kerkling, Serial No. 2,267,033, issued December 23', 1941.

The next step is to drill across the crack 14 to install an ice Allen screw, as best shown in Fig. 3. For this purpose there is solid metal between the valve ports 12 and 13, but starting a drill on the smooth upper surface of the cylinder block 10 presents a real problem; however, with my novel drill brace, or guide, this is readily accomplished. If the crack to be repaired were between the valve port 13 and the cylinder bore 11, the hole should be drilled from left to right in Fig. l; but since the crack to be repaired is from the valve port 12 into the cylinder bore 11, the drilling should be accomplished from right to left, in Fig. 1, so as to start the drill over solid metal and extend downwardly across the crack and through the metal on the other side and into the space provided for the liquid coolant, as shown in Fig. 2.

Because it may be desired to drill from left to right to repair cracks in certain positions, and from right to left to repair cracks in certain other positions, my novel drill brace comprises a pair of tubular guides 17, 17' which lie in spaced relationship in substantially the same vertical plane but have their adjacent ends tilted downwardly through an angle of approximately 30, and the tubes are fixed in this position by welding, respectively, to upstanding flanges 18, 18 on the floor plate 19 which is adjustably held in position on base plate 20 by means of cap screws 21 and clamp 22. The tubular guides 17, 17' have their lower ends beveled to lie in a plane substantially the same or only slightly above the plane of the bottom of the base plate 20; and the guides are hollow tubes open at both ends to receive and guide a drill therethrough. For quickly and easily positioning the tool in fixed relation to a cylinder bore, the base plate 20 is provided with a Van Norman expander which has a plurality of plates 23, 23, 23 spaced about the screw threaded central bolt 24 upon which the riders 25, 25' operate to expand or contract the plates 23, 23, 23 in well known manner.

With the expander in place in the cylinder bore, the drill brace can be swung about to position the tubular guide 17 as shown in Fig. 1 for drilling from right to left across the crack 14. The expander can then be secured in place by tightening the head 26, and final adjustment of the drill brace can be made before tightening the cap screws 21. With my drill brace thus positioned and secured in place a hole can be drilled downwardly at an angle from between the valve ports, across the crack and into the space for cooling liquid. The steps embraced in this operation are described as follows:

Using my drill guide fixture, a hole is drilled from the upper surface of the cylinder block downwardly at an angle, as shown in Figs. 2 and 3, far enough to receive all or most of the head of an Allen screw; then the hole is continued, using a 7 drill bit, to a depth slightly past the crack; then using a 'y drill the bore is continued into the coolant space. The next step is to thread the bore with a tap and install an Allen screw 27, as shown in Fig. 3, with the head embedded in the cylinder block, the shank crossing the crack, and the screw threaded portion on the side of the crack opposite the crack pulling the crack together and locking the previously installed plug 16 securely in place.

A sleeve 28 may then be installed in the cylinder bore in the usual manner. The next step is to channel the crack 14 on top of the block 10 from the valve port 12 up to the sleeve 28; then the crack is punch pricked inside the valve port 12. Then the crack is welded where channelled and punch pricked, being sure that the weld inside the valve port penetrates far enough into the plug 16 at the bottom of the valve seat recess so that the bond between the weld and the plug will not be broken by cutting for a new valve seat. Also, the recess at head of the Allen screw 27 is filled in by welding, as shown at 29 in Fig. 3. By smoothly grinding away the excess weld from the top of the block and from the valve seat recess, a

new valve seat may be installed and the repair job is complete.

Having thus described an embodiment of my novel method and apparatus, it will be obvious to those skilled in the art that numerous changes and modifications can be made without departing from the scope of my invention as defined in the appended claims.

I claim:

1. In a method of repairing a crack in a cylinder block in which the crack extends from a valve port into a cylinder bore in said block, drilling longitudinally through the crack from the base of the valve seat into the cylinder bore, threading the bore thus drilled and plugging said threaded bore, drilling across the crack from the upper surface of the cylinder block downwardly at an angle, pulling the Walls of the crack toward each other by means installed in the hole drilled across the crack, and welding the crack.

2. In a method of repairing a crack in a cylinder block in which the crack extends from a valve port into a cylinder bore in said block, drilling longitudinally through the crack from the base of the valve seat into the cylinder bore, threading the bore thus drilled and plugging said threaded bore, drilling across the crack from the upper surface of the cylinder block downwardly at an angle of approximately 30, pulling the walls of the crack toward each other by means installed in the hole drilled across the crack, and welding the crack.

3. In a method of repairing a crack in a cylinder block in which the crack extends from a valve port into a cylinder bore in said block, drilling longitudinally through the crack from the base of the valve seat into the cyl inder bore, threading the bore thus drilled and plugging said threaded bore, drilling across the crack from the upper surface of the cylinder block downwardly at an angle of approximately 30, pulling the walls of the crack toward each other by means installed in the hole drilled across the crack, channeling the crack on top of said cylinder block, punch pricking along the crack inside the valve port, and welding the crack where channeled and punch pricked.

4. In a method of repairing a crack in a cylinder block in which the crack extends from a valve port into a cylinder bore in said block, drilling through the crack from the base of the valve seat into the cylinder bore, threading the bore thus drilled and plugging said threaded bore, drilling in a direction across the crack from the upper surface of the cylinder block downwardly at an angle of approximately 30, continuing said last mentioned drilling operation with a lesser diameter to a depth slightly past the crack, further continuing said last mentioned drilling operation with a still smaller diameter, threading said still smaller diameter, pulling the walls of the crack toward each other by means installed in the hole drilled across the crack, and welding the crack.

5. In a method of repairing a crack in a cylinder block in which the crack extends from a valve port into a cylinder bore in said block, drilling through the crack from the base of the valve seat into the cylinder bore, threading the bore thus drilled and plugging said threaded bore, drilling in a direction across the crack from the upper surface of the cylinder block downwardly at an angle of approximately 30, continuing said last mentioned drilling operation with a lesser diameter to a depth slightly past the crack, further continuing said last mentioned drilling operation with a still smaller diameter into the coolant space, threading said still smaller diameter, pulling the Walls of the crack toward each other by means installed in the hole drilled across the crack, channeling the crack on top of said cylinder block, punch pricking along the crack inside the valve port, and welding the crack where channeled and punch pricked.

References Cited in the file of this patent UNITED STATES PATENTS 1,128,970 Godefroy et al. Feb. 16, 1915 2,011,484 Harman Aug. 13, 1935 2,121,692 Hays June 21, 1938 2,191,485 Jensen Feb. 27, 1940 2,198,167 Harman Apr. 23, 1940 2,267,033 Kerkling Dec. 23, 1941 2,361,106 Jensen Oct. 24, 1944 2,423,164 Williams July 1, 1947 2,446,291 McAfee Aug. 3, 1948 2,482,925 Mercer Sept. 27, 1949 2,649,650 Javor Aug. 25, 1953 

